Which of the following Anti-psychotic drug has maximum chances of causing hyperprolactinemia?
**Core Concept**
Hyperprolactinemia is a condition characterized by elevated levels of prolactin in the blood, which can be caused by various factors including medications. In the context of antipsychotics, certain drugs are more likely to induce hyperprolactinemia due to their effects on dopamine receptors, particularly D2 receptors, which are involved in regulating prolactin secretion.
**Why the Correct Answer is Right**
The correct answer is **Risperidone**. Risperidone is a second-generation antipsychotic with a high affinity for D2 receptors, which leads to a significant blockade of dopamine receptors in the pituitary gland. This blockade decreases the inhibitory effect of dopamine on prolactin secretion, resulting in increased prolactin levels. Additionally, Risperidone's active metabolite, 9-hydroxyrisperidone, also contributes to its hyperprolactinemic effects.
**Why Each Wrong Option is Incorrect**
* **Option A:** Haloperidol is a first-generation antipsychotic with a high affinity for D2 receptors, but it is less likely to cause hyperprolactinemia compared to Risperidone due to its lower potency and shorter half-life.
* **Option B:** Olanzapine is a second-generation antipsychotic with a lower affinity for D2 receptors compared to Risperidone, making it less likely to induce hyperprolactinemia.
* **Option D:** Quetiapine is another second-generation antipsychotic with a lower affinity for D2 receptors, which reduces its potential to cause hyperprolactinemia.
**Clinical Pearl / High-Yield Fact**
When prescribing antipsychotics, it is essential to consider the risk of hyperprolactinemia, particularly in patients with a history of prolactin-related disorders or those taking medications that may interact with prolactin levels.
**Correct Answer:** C. Risperidone.